Railway truck bolster snubber



Oct. 29, 1968 w. D. WALLACE ET AL 3,407,752

RAILWAY TRUCK BOLSTER SNUBBER Filed March 22, 1966 76 ZZ/LZZz'amfl Mal ace,

. 3 ieizkizllaan/ 30- J United States Patent 3,407,752 RAILWAY TRUCK BOLSTER SNUBBER William D. Wallace and Robert L. Carlson, Chicago, Ill.,

assignors to W. H. Miner, Inc., Chicago, Ill., a corporation of Delaware Filed Mar. 22, 1966, Ser. No. 536,414 3 Claims. (Cl. 105-197) ABSTRACT OF THE DISCLOSURE A snubber assembly mountable between the primary frame and the bolster frame of a railway car, wherein the mounting means accommodates universal movement of the damper relative to the frames, and wherein the snubber comprises a vertically disposed casing filled with a compressible solid and an orificed piston movable therethrough to dampen the oscillations of the bolster frame relative to the primary frame.

Our present invention relates to a snubber assembly adapted to be operatively associated in a railway truck between the primary frame and the secondary or bolster frame thereof.

It is an object of our present invention to provide a snubber assembly, as described, which is comprised of a novel form of damper and novel means for mounting the same between the primary frame and the bolster frame.

It is another object of our present invention to provide a snubber assembly, as described, wherein the damper incorporates a confined compressible solid for producing damping forces.

It is another object of our present invention to provide a snubber assembly, as described, wherein the damper is generally vertically disposed and serves to dampen oscillations of the bolster frame relative to the primary frame in both upward and downward directions.

It is a further object of our present invention to provide a snubber assembly, as described, wherein the mounting means accommodates substantially universal movement of the damper relative to the frames, for example, in planes extending longitudinally and transversely of the primary frame.

It is a still further object of our present invention to provide a snubber assembly, as described, which may be incorporated in a standard railway truck Without modification of the spring means that resiliently supports the bolster frame on the primary frame.

Now in order to acquaint those skilled in the art with the manner of constructing and using snubber assemblies in accordance with the principles of our present invention, we shall describe in connection with the accompanying drawing a preferred embodiment of our invention.

In the drawing:

FIGURE 1 is a fragmentary view of a railway truck and a side elevational view of the snubber assembly of our present invention incorporated therewith;

FIGURE 2 is a front elevational view, on an enlarged scale, of the snubber assembly of FIGURE 1;

FIGURE 3 is a generally median sectional view, on a further enlarged scale, of the snubber assembly of FIG- URE 1, taken substantially along the line 3-3 in FIG- URE 1, looking in the direction indicated by the arrows; and

FIGURE 4 is a transverse sectional view, taken substantially along the line 44 in FIGURE 3, looking in the direction indicated by the arrows.

Referring now to FIGURE 1, there is indicated generally by the reference numeral a portion of a standard railway truck which includes a primary frame having 3,407,752 Patented Oct. 29, 1968 a longitudinally extending side frame element 12, and a secondary or bolster frame 14 overlying and extending transversely of the primary frame 12. The bolster frame 14 is resiliently supported at its ends on the primary frame 12 by conventional spring means 16 which may, for example, be in the form of a cluster of coil springs 18. In accordance with the principles of our present invention, a snubber assembly, indicated generally by the reference numeral 20, is incorporated between the pri mary frame 12 and the bolster frame 14. More specifically, the snubber assembly 20 includes a damper 22 and means for mounting the same between the primary frame 12 and the bolster frame 14.

As shown in FIGURES 3 and 4, the damper 22 comprises an elongated casing or cylinder 24. Mounted within the casing 24, adjacent each end thereof, is a guide and seal assembly 26. Each assembly 26 comprises an outer piston rod hearing or gland 28 having an outwardly facing annular shoulder 30 and an inwardly extending annular flange portion 32. The piston rod bearing 28 is restrained against outward movement by means of four ring segments 34 which engage the bearing shoulder 30 and are received in an annular groove 36 in the casing 24. Slidably mounted in the bearing flange 32 is the reduced end of an inner annular floating sleeve member 38 which carries an O-ring or seal 40 that engages the inner wall of the casing 24. Interposed between the bearing 28 and the sleeve member 38 within the confines of the flange portion 32 are a seal 42 formed of a soft pliable material such as Teflon impregnated asbestos, and an anti-extrusion ring 44. The sleeve members 38 of each assembly 26 serve to define with the casing 24 a chamber 46.

Slidably guided in the piston rod bearings 28 is a piston rod 48 of uniform cross-sectional area. The piston rod 48 extends through the chamber 46, the sleeve members 38, the seal 42, and the antiextrusion rings 44. The piston rod 48 is provided, within the chamber 46 with a piston 50. The periphery of the piston Sll is spaced from the interior of the chamber 46 to define an annular orifice therebetween. For damping purposes, as will be explained hereinafter, the chamber 46 is filled with a compressible solid or elastomer 52 such as silicone rubber. To permit the admission of compressible solid into the chamber 46, and yet prevent the escape of compressible solid therefrom, we provide passageway means 54 and a check valve 56 in the piston rod 48. The compressible solid 52 is preloaded to an initial pressure that is sufficient to maintain a positive force on both sides of the piston 50 at all times. Also, the compressible solid 52 imposes a pressure on the sleeve members 38 whereby the seals 52 and anti-extrusion rings 44 are maintained in sealing engagement with the adjacent peripheries of the piston rod 48.

The damper 22 is normally vertically disposed as shown in FIGURES l, 2 and 3, and the upper end of the casing 24 is adapted to be mounted to the bolster frame 14 by first mounting means indicated generally by the reference numeral 58. The first mounting means 58 comprises first bracket means 60 suitably secured, as by welding, to the bolster 14, and a yoke member 62 having a shank 64 rotatable in the first bracket means 60 about an axis extending transversely of the primary frame 12. The yoke member 62 has bifurcated arms 66, and opposed trunnions 68, which are suitably secured to the casing 24, are rotatable in the bifurcated. arms 66 about an axis extending longitudinally of the primary frame 12.

The lower end of the piston rod 48 is mounted to the primary frame 12 by second mounting means indicated generally by the reference numeral 70. The second mounting means 70 comprises second bracket means 72 suitably secured, as by welding, to the primary frame 12.

The bracket means 72 includes a pair of upstanding longitudinally spaced flanges 73. The lower reduced end 74 of the piston rod 48 is formed with an open-sided spherical socket 76. A shaft 78, which is rotatable in the second bracket means 72 about an axis extending longitudinally of the primary frame 12, is formed with a central spherical section 80 that is seated in the spherical socket 76.

The snubber assembly 20 operates as follows. Upon impact of the damper 22 in either direction resulting from relative vertical movement between the primary frame 12 and the bolster 14, the piston rod 48 and piston 50 are caused to move axially within the chamber 46 and relative to the casing 24. During such movement, the piston 50 is forced through the compressible solid 52 while the latter is metered through the orifice surrounding the piston 50. As a consequence, the compressible solid 52 produces a damping force on the piston and the piston rod whereby to dampen relative vertical oscillations between the primary frame 12 and the bolster 14. The elements of the damper 22 are returned to, and normally maintained in, the neutral position shown in the drawing by the spring means 16.

Our described snubber assembly 20 is velocity sensitive and dampens oscillations in both upward and downward directions. The degree of dampening required in a particular installation is determined by the mass of the railway car and the characteristics of the spring means 16, and the amount of dampening afforded by the assembly 20 is a function of the area of the orifice surrounding the piston 50. Additionally, by reaso of provision of the novel first and second mounting means 58 and 70, which include pivotal connections as described, substantially universal rocking movement of the damper 22 relative to the frame 12 and 14 is accommodated. Thus, the damper 22 has freedom of motion, for example, in planes extending longitudinally and transversely of the primary frame 12. Still further, our snubber assembly 20 is adapted to be incorporated in a standard railway truck, and does not require any modification of the conventional spring means 16. Also, because a confined compressible solid is used in the damper to produce damping forces, the assembly 20 requires minimum maintenance and has a long service life. Finally, as will be appreciated, a snubber assembly 20 may be mounted at each end of the bolster 14.

While we have shown and described what we believe to be a preferred embodiment of our present invention, it will be understood by those skilled in the art that various rearrangements and modifications may be made therein without departing from the spirit and scope of our invention.

We claim:

1. In combination with a railway truck having a primary frame, a bolster frame overlying and extending transversely of the primary frame, and coil spring means disposed between said frames for resiliently supporting said bolster frame on said primary frame, a damper operably connected between said frames for damping generally vertical oscillations therebetween, said damper comprising a vertically disposed cylinder, piston rod guide means sealingly mounted in each end of said cylinder and defining a chamber therebetween, a double-ended piston rod of uniform diameter extending through said cylinder and both of said piston rod guide means and having an axially orificed piston on the portion thereof disposed in said chamber, and a compressible solid filling said chamber for providing a damping force on any relative axial movement between said cylinder and said piston and piston rod, first means for connecting the upper end of said damper to said bolster frame comprising a yoke member having a shank portion operably connected to said bolster frame for rotation about a horizontal axis extending transversely of said primary frame and having a pair of spaced arms provided with a pair of aligned bores, and a pair of diametrically opposite radially extending trunnions provided on the upper end of said cylinder and mounted in said aligned bores provided in said spaced arms of said yoke member for rotation about a horizontal axis extending longitudinally of said primary frame, and second means for operably connecting the lower end of said damper to said primary frame comprising a spherical socket formed in the lower end of said piston rod, and a shaft mounted on said primary frame for rotation about a horizontal axis extending longitudinally of said primary frame and having a spherical section seated in said spherical socket in the lower end of said piston rod, said first and second damper connecting means accommodating relative movement between said primary and bolster frames other than pure vertical movement.

2. The combination of claim 1 wherein each of said damper piston rod guide means comprises a piston rod guide bearing mounted in an end of said cylinder and having an annular recess formed on its inner face adjacent said piston rod, seal means disposed in said recess and about said piston rod, and a floating sleeve member disposed about said piston rod inwardly of said piston rod guide bearing and having a portion in sealing engagement with the inner surface of said cylinder and a reduced-in-diameter portion slidably receivable in said bearing recess for exerting sealing pressure on said seal means disposed therein.

3. The combination of claim 1 wherein the upper end portion of said piston rod is provided with passage means extending into said chamber and including check valve means whereby to facilitate filling said chamber with said compressible solid.

References Cited UNITED STATES PATENTS 2,516,082 7/1950 Spencer l05193 2,705,633 4/1955 Potter et a1. -197 2,710,582 6/1955 Travilla 105-197 XR 3,053,526 9/1962 Kendall 105101 XR ARTHUR L. LA POINT, Primary Examiner. H. BELTRAN, Assistant Examiner. 

